/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.regionserver;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.CompareOperator;
import org.apache.hadoop.hbase.client.Append;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Durability;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Increment;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Row;
import org.apache.hadoop.hbase.client.RowMutations;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.coprocessor.Batch.Call;
import org.apache.hadoop.hbase.client.coprocessor.Batch.Callback;
import org.apache.hadoop.hbase.client.metrics.ScanMetrics;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;

import com.google.protobuf.Descriptors.MethodDescriptor;
import com.google.protobuf.Message;
import com.google.protobuf.Service;
import com.google.protobuf.ServiceException;

/**
 * An implementation of {@link Table} that sits directly on a Region; it decorates the passed in
 * Region instance with the Table API. Some API is not implemented yet (throws
 * {@link UnsupportedOperationException}) mostly because no need as yet or it necessitates copying
 * a load of code local from RegionServer.
 *
 * <p>Use as an instance of a {@link Table} in-the-small -- no networking or servers
 * necessary -- or to write a test that can run directly against the datastore and then
 * over the network.
 */
public class RegionAsTable implements Table {
    private final Region region;

    /**
     * @param region Region to decorate with Table API.
     */
    public RegionAsTable(final Region region) {
        this.region = region;
    }

    @Override
    public TableName getName() {
        return this.region.getTableDescriptor().getTableName();
    }

    @Override
    public Configuration getConfiguration() {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public HTableDescriptor getTableDescriptor() throws IOException {
        return new HTableDescriptor(this.region.getTableDescriptor());
    }

    @Override
    public TableDescriptor getDescriptor() throws IOException {
        return this.region.getTableDescriptor();
    }

    @Override
    public boolean exists(Get get) throws IOException {
        if(!get.isCheckExistenceOnly())
            throw new IllegalArgumentException();
        return get(get) != null;
    }

    @Override
    public boolean[] exists(List<Get> gets) throws IOException {
        boolean[] results = new boolean[gets.size()];
        int index = 0;
        for(Get get : gets) {
            results[index++] = exists(get);
        }
        return results;
    }

    @Override
    public void batch(List<? extends Row> actions, Object[] results) throws IOException, InterruptedException {
        throw new UnsupportedOperationException();
    }

    @Override
    public <R> void batchCallback(List<? extends Row> actions, Object[] results, Callback<R> callback) throws IOException, InterruptedException {
        throw new UnsupportedOperationException();
    }

    @Override
    public Result get(Get get) throws IOException {
        return this.region.get(get);
    }

    @Override
    public Result[] get(List<Get> gets) throws IOException {
        Result[] results = new Result[gets.size()];
        int index = 0;
        for(Get get : gets) {
            results[index++] = get(get);
        }
        return results;
    }

    static class RegionScannerToResultScannerAdaptor implements ResultScanner {
        private static final Result[] EMPTY_RESULT_ARRAY = new Result[0];
        private final RegionScanner regionScanner;

        RegionScannerToResultScannerAdaptor(final RegionScanner regionScanner) {
            this.regionScanner = regionScanner;
        }

        @Override
        public Iterator<Result> iterator() {
            throw new UnsupportedOperationException();
        }

        @Override
        public Result next() throws IOException {
            List<Cell> cells = new ArrayList<>();
            return regionScanner.next(cells) ? Result.create(cells) : null;
        }

        @Override
        public Result[] next(int nbRows) throws IOException {
            List<Result> results = new ArrayList<>(nbRows);
            for(int i = 0; i < nbRows; i++) {
                Result result = next();
                if(result == null)
                    break;
                results.add(result);
            }
            return results.toArray(EMPTY_RESULT_ARRAY);
        }

        @Override
        public void close() {
            try {
                regionScanner.close();
            } catch(IOException e) {
                throw new RuntimeException(e);
            }
        }

        @Override
        public boolean renewLease() {
            throw new UnsupportedOperationException();
        }

        @Override
        public ScanMetrics getScanMetrics() {
            throw new UnsupportedOperationException();
        }
    }

    ;

    @Override
    public ResultScanner getScanner(Scan scan) throws IOException {
        return new RegionScannerToResultScannerAdaptor(this.region.getScanner(scan));
    }

    @Override
    public ResultScanner getScanner(byte[] family) throws IOException {
        return getScanner(new Scan().addFamily(family));
    }

    @Override
    public ResultScanner getScanner(byte[] family, byte[] qualifier) throws IOException {
        return getScanner(new Scan().addColumn(family, qualifier));
    }

    @Override
    public void put(Put put) throws IOException {
        this.region.put(put);
    }

    @Override
    public void put(List<Put> puts) throws IOException {
        for(Put put : puts)
            put(put);
    }

    @Override
    @Deprecated
    public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, byte[] value, Put put) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value, Put put) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, CompareOperator compareOp, byte[] value, Put put) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public void delete(Delete delete) throws IOException {
        this.region.delete(delete);
    }

    @Override
    public void delete(List<Delete> deletes) throws IOException {
        for(Delete delete : deletes)
            delete(delete);
    }

    @Override
    public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, byte[] value, Delete delete) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value, Delete delete) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, CompareOperator compareOp, byte[] value,
            Delete delete) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public CheckAndMutateBuilder checkAndMutate(byte[] row, byte[] family) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void mutateRow(RowMutations rm) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public Result append(Append append) throws IOException {
        return this.region.append(append);
    }

    @Override
    public Result increment(Increment increment) throws IOException {
        return this.region.increment(increment);
    }

    @Override
    public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount, Durability durability) throws IOException {
        throw new UnsupportedOperationException();
    }

    /**
     * This call will NOT close the underlying region.
     */
    @Override
    public void close() throws IOException {
    }

    @Override
    public CoprocessorRpcChannel coprocessorService(byte[] row) {
        throw new UnsupportedOperationException();
    }

    @Override
    public <T extends Service, R> Map<byte[], R> coprocessorService(Class<T> service, byte[] startKey, byte[] endKey,
            Call<T, R> callable) throws ServiceException, Throwable {
        throw new UnsupportedOperationException();
    }

    @Override
    public <T extends Service, R> void coprocessorService(Class<T> service, byte[] startKey, byte[] endKey, Call<T, R> callable,
            Callback<R> callback) throws ServiceException, Throwable {
        throw new UnsupportedOperationException();
    }

    @Override
    public <R extends Message> Map<byte[], R> batchCoprocessorService(MethodDescriptor methodDescriptor, Message request, byte[] startKey,
            byte[] endKey, R responsePrototype) throws ServiceException, Throwable {
        throw new UnsupportedOperationException();
    }

    @Override
    public <R extends Message> void batchCoprocessorService(MethodDescriptor methodDescriptor, Message request, byte[] startKey, byte[] endKey,
            R responsePrototype, Callback<R> callback) throws ServiceException, Throwable {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndMutate(byte[] row, byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value,
            RowMutations mutation) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public boolean checkAndMutate(byte[] row, byte[] family, byte[] qualifier, CompareOperator compareOp, byte[] value,
            RowMutations mutation) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public void setOperationTimeout(int operationTimeout) {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public int getOperationTimeout() {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public void setRpcTimeout(int rpcTimeout) {
        throw new UnsupportedOperationException();
    }

    @Override
    public long getReadRpcTimeout(TimeUnit unit) {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public void setWriteRpcTimeout(int writeRpcTimeout) {
        throw new UnsupportedOperationException();
    }

    @Override
    public long getOperationTimeout(TimeUnit unit) {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public void setReadRpcTimeout(int readRpcTimeout) {
        throw new UnsupportedOperationException();
    }

    @Override
    public long getWriteRpcTimeout(TimeUnit unit) {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public int getRpcTimeout() {
        throw new UnsupportedOperationException();
    }

    @Override
    public long getRpcTimeout(TimeUnit unit) {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public int getWriteRpcTimeout() {
        throw new UnsupportedOperationException();
    }

    @Override
    @Deprecated
    public int getReadRpcTimeout() {
        throw new UnsupportedOperationException();
    }
}
